{"cve":"CVE-2026-52999","nvd":{"published":"2026-06-24T17:17:10.913","modified":"2026-10-19T20:18:54.340","status":"Modified","description":"In the Linux kernel, the following vulnerability has been resolved:\n\nnetfilter: nfnetlink_osf: fix out-of-bounds read on option matching\n\nIn nf_osf_match(), the nf_osf_hdr_ctx structure is initialized once\nand passed by reference to nf_osf_match_one() for each fingerprint\nchecked. During TCP option parsing, nf_osf_match_one() advances the\nshared ctx->optp pointer.\n\nIf a fingerprint perfectly matches, the function returns early without\nrestoring ctx->optp to its initial state. If the user has configured\nNF_OSF_LOGLEVEL_ALL, the loop continues to the next fingerprint.\nHowever, because ctx->optp was not restored, the next call to\nnf_osf_match_one() starts parsing from the end of the options buffer.\nThis causes subsequent matches to read garbage data and fail\nimmediately, making it impossible to log more than one match or logging\nincorrect matches.\n\nInstead of using a shared ctx->optp pointer, pass the context as a\nconstant pointer and use a local pointer (optp) for TCP option\ntraversal. This makes nf_osf_match_one() strictly stateless from the\ncaller's perspective, ensuring every fingerprint check starts at the\ncorrect option offset.","cvss_v4":null,"cvss_v3":{"version":"3.1","vector":"CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:H/I:N/A:H","score":9.1},"cwes":["CWE-125"],"references":["https://git.kernel.org/stable/c/0145548346c4a30981a870a8ca00eac46ba27e85","https://git.kernel.org/stable/c/1c136f2c44a5913646bac85303612fd0825197a0","https://git.kernel.org/stable/c/1e19a07291bb8682c14c39a64725a3ae54ab8ccc","https://git.kernel.org/stable/c/21883587593d7c8bb519a79460a0b5bc5ffbdabd","https://git.kernel.org/stable/c/32e50f92c7cf3f4eba29622179a5fcdc2aebab41"],"products":["linux:linux_kernel"],"source":"nvd","synced_at":"2026-10-21T03:43:09.190223697+00:00"},"epss":{"cve":"CVE-2026-52999","score":0.00591,"percentile":0.47971,"date":"2026-10-25"},"kev":null,"osv":[],"attribution":["This product uses the NVD API but is not endorsed or certified by the NVD.","EPSS scores: FIRST Exploit Prediction Scoring System, https://www.first.org/epss","Known exploited vulnerabilities: CISA Known Exploited Vulnerabilities Catalog, https://www.cisa.gov/known-exploited-vulnerabilities-catalog","Package advisories: OSV (https://osv.dev), from the GitHub Advisory Database, PyPA, Go, RustSec and other ecosystem databases, under CC-BY 4.0 or CC0","CVE records: the CVE Program's CVE List (https://www.cve.org), under its terms of use (https://www.cve.org/Legal/TermsOfUse). CVE is a registered trademark of The MITRE Corporation; this product is not affiliated with the CVE Program."]}